The present invention relates to disc brakes and more particularly to a floating type disc brake for use with a two-wheeled vehicle such as a bicycle or motorcycle.
A caliper floating type disc brake as shown in FIGS. 1 through 3 is well known as a disc brake of simple construction which can be readily mounted on the fork of a two-wheeled vehicle. This brake is advantageous in that it is unnecessary to use mounting parts such as a bracket and its securing bolts and the brake is simple in construction. However, this brake is still disadvantageous in that it is so designed that a pin running through the stationary member receives the brake torque which results when the vehicle is moved backward. Because of this, the rubber bushing on the pin has a tendency to crack.
This will be described in more detail. In FIGS. 1 through 3, reference character A designates a disc; 11 and 12, pad assemblies; and 13, a caliper cylinder. In this conventional disc brake, protrusions 3 and 4 are provided in the front and rear regions of the side 2 of the caliper 1 on either side of a stationary member 6 which is integral with the fork 5 of the vehicle or which is mounted on the fork 5. The stationary member 6 has a through-hole 7. The caliper 1 is mounted on the fork 5 by inserting a pin 8 into the through-hole 7 and the two protrusions 3 and 4. It should be noted that an elastic bushing 9 made of, for instance, rubber is disposed in the through-hole 7. The elastic bushing 9 serves to absorb and eliminate variations in dimension of the side 2 of the caliper, the flat surface 10 of the stationary member 6, and the through-hole 7.
In the disc brake described above, when the vehicle moves forward, the brake torque is received by the flat surface 10 of the stationary member 6 abutting against the side 2 of the caliper 1 as the disc A turns in the direction of the arrow in FIG. 1. When the vehicle moves backward, the brake torque is received by the pin 8 running through the stationary member 6.
When the brake torque resulting from backward movement is received by the pin 8, the bushing 9 disposed in the through-hole 7 and surrounding the pin 8 is compressed and deformed. If the compression force is great, the bushing 9 may crack.
Accordingly, an object of the present invention is to provide a disc brake for a two-wheeled vehicle in which the bushing disposed in the through-hole for absorbing the dimensional variations is so designed that it will not crack even if it is subjected to high compression and accordingly to great deformation.